(under the class definition) Subject matter wherein the oscillator system is provided (1) with means for shielding at least part of the oscillator system from external electric or magnetic fields, (2) with means to shield one or more parts of the oscillator system from electric or magnetic fields generated in one or more other parts of the oscillator system, (3) with shielding or screening means to prevent radiation of undesired electric or magnetic fields generated within the oscillator system.
(1) Note. The electric or magnetic shield or screen to be classified herein must be in addition to and separate from oscillator circuit element structure. For example, if the electron tube of the oscillator contains a screen grid orshielding electrode as a perfecting feature of the tube this is considered tube structure and not shielding or screening for this subclass. Subclasses 72+ for instance, is directed to electron coupled oscillators utilizing tetrode or pentode tubes wherein the screen electrode shields or screens the oscillator circuit section of the tube from the output or anode circuit thereof. Another example of excluded subject matter is that of an oscillator wherein the resonator of the oscillator encloses and forms a screen for the active element of the oscillator (see subclasses 97+, for example, for a tube enclosed by a distributed parameter type resonator).
(2) Note. The shield or screen must be claimed as a magnetic, electric or electromagnetic shield or screen, or such limitations must be recited to clearly restrict the shield or screen to that use, to cause classification in this subclass. Merely reciting the combination of an oscillator with an outer casing or housing, or as a metallic outer casing or housing, for example, would not be sufficient for classification herein, such combination being classified in subclasses 68+ below.
SEE OR SEARCH THIS CLASS, SUBCLASS:
68+, for oscillators combined with outer casing or housing. See (2) Note above.
72+, for electron coupled oscillators utilizing screen grid
tubes. See (1) Note above. 79+, for beam tube oscillators wherein part of the tube structure may include electric or magnetic shielding means.
86+, for magnetically controlled space discharge device oscillators wherein part of the discharge device may include electric or magnetic shielding means.
97+, for oscillators wherein the oscillator tube is enclosed by a distributed parameter resonator of the oscillator. (See (1) Note above).
SEE OR SEARCH CLASS
174, Electricity: Conductors and Insulators,
32+, for miscellaneous anti-inductive structures, see particularly indented subclasses 35+, for miscellaneous electrical shields and screen structures not elsewhere classifiable. The search notes to subclasses 32+, indicate further fields of search for anti-inductive and shielding structure.
